1. Field of the Invention
The present invention relates to an image reading apparatus having a transmission function and a control method therefor.
2. Description of the Related Art
An image forming apparatus such as an MFP (multi function peripheral) is generally provided with an image reading apparatus for reading originals. In recent years, even a low-priced image reading apparatus has a transmission function for converting read original image data into a file format specified by a user and transmitting the resultant data to a specified destination according to a predetermined protocol.
For image data transmission by the transmission function, accumulation type transmission, successive type transmission, or the like is used.
The accumulation type transmission refers to a technique of reading all originals to be transmitted, temporarily storing image data into a storage of an MFP, and transmitting the image data stored in the storage.
Although the accumulation type transmission requires a large-capacity storage capable of storing a large amount of image data, it can transmit the same image data any number of times so long as the image data is not erased from the storage. It is therefore possible to transmit the image data simultaneously to different destinations.
In the accumulation type transmission, the original image data is retained in the storage, and therefore so-called simultaneous transmission can be achieved even in the case of using a transmission protocol requiring that different pieces of header information be added to respective ones of image data for different destinations.
In the accumulation type transmission, image data to be transmitted is stored in the storage, as previously described. Thus, a recovery process can be carried out in a case, for example, that transmission of image data has failed. Furthermore, since all originals are read before start of transmission of image data, a user can leave the image reading apparatus immediately after the originals are read and before completion of processing for the transmission.
The successive type transmission refers to a technique of transmitting image data of original each time one sheet of original is read. In the successive type transmission, the transmitted image data is immediately erased from the storage.
The successive type transmission is functionally inferior to the accumulation type transmission since the above-described advantageous operations of the accumulation type transmission are restricted in the successive type transmission. With the successive type transmission, however, transmission can be carried out provided that the storage has a capacity corresponding to at least image data of one sheet of original.
Even in a low-priced image reading apparatus, high user-friendliness is requested. For example, the provision of the following functions is demanded.
(1) Function of reconfirming a user's intention when the user performs an operation to cancel a transmission job which is in execution, thereby reducing an operation mistake.
(2) Function capable of executing, as one job, processing for transmission of image data of plural sheets of originals even in a reading mode in which each time an original placed on an original platen (original placement table) has been read, an inquiry is made to the user about whether the next original is to be read and in which if the original placed on the original platen is replaced by the next original, the next original is read.
Japanese Laid-open Patent Publication No. H9-046490 discloses an image forming apparatus that enables a user to confirm a recovery operation, which is performed when a jam takes place in an ADF (auto document feeder). Japanese Laid-open Patent Publication No. 2002-223338 discloses an image reading apparatus capable of continuously and alternately performing reading in a mode in which an original placed by a user on an original table is read and reading in a mode in which an original fed from the ADF onto the original table is read. This image reading apparatus performs control to change the reading mode at a specified page to another reading mode, if an interruption instruction is given when reading is being performed in either one of the reading modes. After completion of the reading in the reading mode after the mode change, it is determined whether there is an original which is the same type as the originals read in the previous reading mode. If there is such an original, the previous reading mode is resumed.
For a low-priced image reading apparatus, successive type transmission capable of suppressing the storage capacity as compared to accumulation type transmission is sometimes used.
Even in a low-priced image reading apparatus, various processing for transmission of image data obtained by reading plural sheets of originals are sometimes handled as one job, while making an inquiry to a user about whether the next original is to be read each time an original has been read. This is a case, for example, where after one sheet of original placed on the original platen of the image reading apparatus is read, a user replaces the original by the next original and gives an instruction to read the next original. In that case, the image reading apparatus waits for a user's instruction after reading one sheet of original. In the successive type transmission, a session with a transmission destination apparatus is established at a timing to transmit image data obtained by reading the first one of originals. If a predetermined time period has elapsed while the image reading apparatus is waiting for a user's instruction, a session timeout takes place depending on a transmission protocol selected at the time of transmission, so that a job which is being processed is discontinued.
In an image reading apparatus that employs the successive type transmission, an instruction to cancel a job is sometimes given by a user while an original is being read or image data is being transmitted. In such a case, the image reading apparatus does not immediately cancel the job which is in execution, but cancels the job after an instruction to confirm that the job is to be canceled is given by the user. In other words, the image reading apparatus waits for the user's job cancellation confirmation instruction after receiving the user's job cancellation instruction. Depending on the transmission protocol, there is a case where a session timeout takes place while the image reading apparatus is waiting for the job cancellation confirmation instruction, so that the job is discontinued.